27 August 2013

Present: Lee, Tom (scribe), David, Kyle, Jake, Daniel, Kwaku (he could see us, we couldn’t see him)

Semester meeting time: Wednesdays from 10AM to noon, starting next week.

Lee’s To Do:

  • Edit info on website.
  • Merge changes into Clojush, including Tom’s pull request and Kyle’s RNG code.

Clojush RNG

Things aren’t too bad, so we don’t have to do anything drastic like redo all of our runs. Kyle’s new code should solve the problem, at least as well as can be done using Java’s RNG.

Lexicase Speed

Tom will try out making error lists into error vectors, which should hopefully speed up lexicase. More news to follow after this has been tested.


  • Uses rule-based evolution for ghost team vs. Ms. Pac-Man
  • Uses ECJ!
  • Seems related to other rule-based systems and learning classifier systems


  • Lee has ideas for making ventpods create waste
  • Programming is getting there.

Calc Problem Updates

  • Something recently added is helping!
    • Single-digit and double-digit entry tests and single digit math seem to be evolving decently.
  • Changes include:
    • Back to regular lexicase
    • Each “test” generates 2 cases:
      • Numerical difference from desired output
      • Levenshtein distance of string to desired string
      • Important to think about fitness function carefully!
      • Also, a meta test case that counts the number of other test cases that aren’t zero
  • Many no-ops may be helpful!?!?
    • Homology / ULTRA / ???
    • May want to try some sort of ULTRA with pre-specified or evolved “crossover points”

Lexicase Subset Division (Dave’s Idea)

  • Related to spacial co-evolution if we use neighborhoods like trivial geography.
  • How to make lexicase faster by using fewer test cases?

Age-Enhanced Lexicase

Idea: make age a test case used in lexicase selection.

  • Is one age case enough?
  • Other added cases may be helpful!
  • Try on other problems?

One thought on “27 August 2013

  1. Pingback: Past Meeting Notes | Computational Intelligence Laboratory

Leave a Reply

Your email address will not be published. Required fields are marked *